1. Field of the Invention
The present invention relates to a color image processing system, and particularly to an image processing technique for an endoscopic system.
2. Description of the Prior Art
Recently, there has been developed an endoscopic system provided with a solid-state imaging element such as a charge coupled device (CCD) which is arranged at an end of a fiberscope of the endoscopic system. The fiberscope with the imaging element picks up the image of, for instance, an inside wall of a stomach as a color television image to directly display the image on a color CRT for observation. Admitted advantages of the endoscopic system with imaging element are (1) an endoscopic inspection carried out easily, and (2) an image to be displayed being clear. By processing and displaying the image obtained by the fiberscope with imaging element, it is expected to newly improve diagnostic functions.
According to a conventional image diagnosis with an endoscopic system, a morbidity is detected based on the structure (the irregularity of plicae) and the changes in color (coloring, color change, etc.,) of the mucosae of internal organs. In the case of an early cancer for instance, only a delicate change appears in the state of plicae so that the change in structure may not be recognized from observing a color image of the endoscope, and the morbidity may be overlooked.
In this case, if the delicate structure and the color change of the plicae are enhanced, the morbidity may be easily found. However, since the endoscopic image is generally represented by image information comprising three components of red (R), green (G), and blue (B) obtained by a color camera, there is a problem that the color is also changed when the enhancement for, for instance, the structure is carried out on the image comprising the components of R, G, and B.
As mentioned in the above, the conventional technique cannot carry out the enhancing process separately for the structure and for the color of the mucosae of internal organs.
Conventionally, in the image diagnosis with the endoscopic system, morbidity is inspected based on the structure (to be reflected by brightness) and the color change of the mucosae of internal organs. In this case, it is important to diagnose an extent of the morbidity.
When the color is changed delicately due to the morbidity, it is difficult to accurately recognize the color-changed morbid region by the diagnosis on the endoscopic color image.
Further, it is frequently difficult to recognize the delicate color change by the color image because the structure, i.e., an intensity affects the color. For instance, the same color is displayed dark for a distal location and bright for a proximal location. In the same manner, a valley of plicae is displayed dark, and a crest thereof bright. Due to those, it is difficult to observe the delicate tint of plicae.
According to a prior art color image processing system, no means is used to convert the image information comprising R, G, and B components into respective images for intensity, saturation, and hue which are three properties of color, process the respective images, convert the respective images again into the images of R, G, and B components, and display them.